The present invention relates to an inflatable bag, and more particularly to such an inflatable bag which has a collapsible air inlet device, which is compressed by the pressure of the inside air inside the inflatable bag to close the air passage automatically after the inflatable bag has been inflated, and a blow pipe fastened to the collapsible air inlet device through which air is blown through the air inlet device into the inside of the inflatable bag.
FIG. 4 shows an inflatable bag 4 having an air inlet device 41 fastened to a narrow, elongated neck thereof on the inside by a heat sealing apparatus. When inflating the inflatable bag 4, the nozzle tube of an air cylinder is inserted into the air inlet device 41, and then compressed air is released from the air cylinder into the inflatable bag 4, causing the inflatable bag 4 to be inflated. After the inflatable bag 4 has been inflated, the elongated neck 41 is fastened to a support member 6 at one end of a stick 5 to close the air passage of the air inlet device. The procedure of fastening the elongated neck 41 of the inflatable bag 4 to the support member 6 is complicated. Further, because the end of the elongated neck 41 is disposed outside the support member 6, it destroys the sense of beauty of the inflatable bag 4.